21415021351 has 4 divisors (see below), whose sum is σ = 21459729600. Its totient is φ = 21370313104.

The previous prime is 21415021291. The next prime is 21415021393. The reversal of 21415021351 is 15312051412.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21415021351 - 2⁷ = 21415021223 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21415021751) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22353406 + ... + 22354363.

It is an arithmetic number, because the mean of its divisors is an integer number (5364932400).

Almost surely, 2^21415021351 is an apocalyptic number.

21415021351 is a deficient number, since it is larger than the sum of its proper divisors (44708249).

21415021351 is an equidigital number, since it uses as much as digits as its factorization.

21415021351 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44708248.

The product of its (nonzero) digits is 1200, while the sum is 25.

Adding to 21415021351 its reverse (15312051412), we get a palindrome (36727072763).

The spelling of 21415021351 in words is "twenty-one billion, four hundred fifteen million, twenty-one thousand, three hundred fifty-one".